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The dynamic characteristics prediction and frequency-modulation of pipeline was an important work for the design of aircraft hydraulic structure.

A complex pipeline was deemed as a combination of several segments of straight-pipe-element (SPE). The 3D vibration equations of each SPE were established in their local coordinate system based on Timoshenko-beam model and Euler-beam model, respectively. The dynamic-stiffness-matrixes were deduced from the dispersion relation of these equations. According to the complex pipeline layout in the global coordinate system, a multi dynamic stiffness matrixes assembling (MDSMA) algorithm was carried out to establish the characteristic equations of the whole complex pipeline. The MDSMA solutions were verified to be consistent with experimental results.

The MDSMA method based on Timoshenko-Beam model was more suitable for the short span aviation pipeline and the vibration at high frequency stage (>350 Hz). The layout affected the pipeline's in-plane stiffness and out-plane stiffness, for the Z-shaped pipe, each order natural mode took place on the ZP and NP alternately. Reasonable designs of bending position and bending radius were effective means for complex pipeline frequency-modulation.

A new dynamic modeling method of aircraft complex pipeline was proposed to obtain the influence of pipeline layout parameters on dynamic characteristics.

The purpose of this paper is to improve the modeling accuracy of the magnetostrictive hysteretic characteristics by introducing hysteresis energy instead of pinning energy in the assembled domain structure model (ADSM).

First, the magnetostrictive characteristics and the domain movement process in an electrical steel sheet are measured and observed. The reasons for the influence of stress on magnetostriction are discussed on the mesoscopic level. Second, the ADSM model using the hysteresis energy is investigated to estimate the influence of external stress. Finally, the simulation results of the modified ADSM model are compared with the experimental data under the same calculation conditions.

The results show that the improved model not only explains the cause of hysteresis clearly from the perspective of the magnetic moment but also improves the modeling ability of magnetostrictive hysteretic.

The magnetostriction in electrical steel lags behind the external magnetic field, and it is significant for reducing core vibration to estimate the magnetostrictive hysteretic property accurately. This paper proposes an effective approach to model the hysteretic characterization of magnetostriction.

The purpose of this study is to investigate the effects of Ce and Sb doping on the microstructure and thermal mechanical properties of Sn-1.0Ag-0.5Cu lead-free solder. The effects of 0.5%Sb and 0.07%Ce doping on microstructure, thermal properties and mechanical properties of Sn-1.0Ag-0.5Cu lead-free solder were investigated.

According to the mass ratio, the solder alloys were prepared from tin ingot, antimony ingot, silver ingot and copper ingot with purity of 99.99% at 400°C. X-ray diffractometer was adopted for phase analysis of the alloys. Optical microscopy, scanning electron microscopy and energy dispersive spectrometer were used to study the effect of the Sb and Ce doping on the microstructure of the solder. Then, the thermal characteristics of alloys were characterized by a differential scanning calorimeter (DSC). Finally, the ultimate tensile strength (UTS), elongation (EL.%) and yield strength (YS) of solder alloys were measured by tensile testing machine.

With the addition of Sb and Ce, the ß-Sn and intermetallic compounds of solders were refined and distributed more evenly. With the addition of Sb, the UTS, EL.% and YS of Sn-1.0Ag-0.5Cu increased by 15.3%, 46.8% and 16.5%, respectively. The EL.% of Sn-1.0Ag-0.5Cu increased by 56.5% due to Ce doping. When both Sb and Ce elements are added, the EL.% of Sn-1.0Ag-0.5Cu increased by 93.3%.

The addition of 0.5% Sb and 0.07% Ce can obtain better comprehensive performance, which provides a helpful reference for the development of Sn-Ag-Cu lead-free solder.

Leader high performance expectation (LHPE) as a performance management practice is becoming more common in today’s business environment, with managers setting ambitious goals to motivate employees to excel at their jobs. This study aims to critically examine LHPE as a performance management practice within contemporary organizations, focusing on whether LHPE has opposing effects on employee performance and health, as well as how servant leadership can improve the benefits of LHPE while lowering its costs.

A path analysis of data from a three-wave survey of 416 full-time employees was used to test our hypotheses.

LHPE has opposing effects on employees via two distinct pathways: motivational effects on employee performance via harmonious work passion and strain effects on employee health via work strain. In the face of LHPE, servant leadership can assist in achieving a mutual gain between employee performance and health.

This study contributes uniquely to the field of employee relations by offering a comprehensive analysis of LHPE’s dual effects. It moves beyond traditional views that focus on singular outcomes, providing a deeper understanding of how LHPE can both motivate and strain employees. Highlighting servant leadership’s role signifies a novel approach to managing LHPE’s complexities, presenting valuable insights for HR practitioners and organizational leaders. This research underlines the importance of balancing performance expectations with employee well-being, aligning with modern perspectives on positive employment relationships.

Drawing on goal orientation theory, this study intends to investigate whether, how and when developmental leadership influences employees’ feedback seeking behavior (FSB) and feedback avoidance behavior (FAB).

The authors used a two-wave survey of 416 full-time employees in China. The hypotheses were tested with path analyses.

Developmental leadership exerts a positive influence on employees’ FSB and a negative impact on FAB through learning goal orientation (LGO). Additionally, leaders’ high performance expectations (LHPE) not only strengthen the positive effects of developmental leadership on FSB but also intensify its weakening effects on FAB.

The findings enrich current understanding by associating developmental leadership with employees’ FSB/FAB, offering a new viewpoint on its positive impacts. This study also provides deeper insights into when the benefits of developmental leadership are intensified.